Full Floater Rearend - Weight Transfer

A Full Floater Rearend Can Infuse Your Street Car With Race Car Tech

In the last issue we gave you the 411 on floating rearend technology. For those that missed class (and shame on you if you did), it’s race car tech that has migrated over to our street cars, and given how hard our Camaros are being driven these days, it’s a very good thing indeed.

The problem solved by a floater rearend mostly revolves around brake pad knockback. In a traditional rearend the axles support the weight of the car, and under hard cornering they can flex. This flexing, besides causing unpredictable geometry changes, can cause the rotors to push back on the brake pads, forcing the pistons back into the caliper bores. The result is when you hit the brakes, the first pump only resets the pistons back against the pads (and hence the rotor). This necessitates another pump to actually cause the braking action you expected on the first hit of the pedal. Now, you can get used to this, but double pumping your brakes after every hard turn can get a bit old, and besides, do you really need one more thing to think about when you’re out on the track?

A floater is also safer than a traditional flanged axle since there’s no way a wheel can exit the vehicle if an axle snaps. Race teams have also grown fond of them since they can replace a broken axle without even pulling the wheel off the car. Is it necessary for everyone? No, but if you plan on pushing your ride hard, then it’s an option you should really consider.

Several companies have started selling race-bred floater kits designed for street-driven Camaros. These kits have features not found on race cars but are needed for street duty – items like parking brakes and ABS capabilities. Strange Engineering has been selling drag car floaters for some time now, but they’re getting ready to introduce a street version. Based on race-proven components, their retro-fit system combines the best of racetrack tech and street car necessities into one package perfect for the weekend warrior who likes nothing more than flogging his Camaro from time to time. Strange also tried to make the kit as compact as possible so that it would clear various stock suspension mounts. We volunteered Bad Penny, our ’68 Camaro, to be their patient zero and talked Tim Lee, over at Don Lee Auto, into letting us tie up his lift for a few days. Now, in terms of installation, this isn’t something the average guy can knock out in his or her garage. So we hit up Currie Enterprises since they have a ton of experience installing floaters and a bitchin set of tools. So follow along as we show you what’s involved in taking your Camaro one step closer to handling nirvana.

01 And here’s what makes up the floater part of Strange’s kit. They’ve been building drag race floaters for some time, but this is their first kit designed for cars that hit the twisties. The retrofit kit features hardened steel drive plates, 4130 heat-treated spindles, steel hubs, and Timken bearings. The ARP wheel studs come in 1⁄2- or 5⁄8-inch, and the inner axle end can be 31- or 35-spline. The axles are custom cut to the right length for each order and are made of Hy-Tuf steel. The kit will offer ABS compatibility and ship with Wilwood brakes in a variety of rotor sizes and styles.

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02 Since the spindle will support the weight of the car, it has to be made of stout material. Strange can turn down the spindle to fit the ID of your axle tube, but for reasons you will soon see, it’s better to do it at the shop that will be installing them since fitment is critical. If you’re buying a rear housing from them they can also install the spindles at their facility. The 2-inch OD spindles are big enough to accommodate 1.5-inch, 35-spline axles. We installed the kit in a Ford 9-inch housing, but it will work with Dana 60, GM 12-bolt, and other rears.

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03 The rear in our ’68 Camaro was running traditional flanged axles. The problem is that they flex under hard cornering causing pad knockback in the rear brakes. This constant stress also caused the bearings that support the axle to leak and loosen up, which made knockback even worse. A common “Band-aid” is to frequently replace the bearings, especially before a big race.

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04 Over at Currie Enterprises, the first task was to do math, lots of math. After all, our distance from wheel to wheel was 55 inches, and this is what we needed it to be afterwards. Strange provided an engineering diagram, which really helped Currie figure out where to make the cuts. Just like when building a house, measure twice, cut once.

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05 Using a bar and jig to line the spindle up dead center in the housing, Currie found a small issue. It seems that the process of welding on the three-link brackets warped the axles tubes. Now this isn’t as critical with traditional axles, and the ends can be welded on slightly off center to account for the warpage. But with a floater, the centering is critical since being off center will cause stress and increased wear on the splined ends of the axles.

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06 After doing more math, the wizards at Currie put the spindle on the jig and off-center milled it. This way when the spindle slides into the axle tube the hole will be dead center through the third member and into the other spindle.

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07 Four 5⁄8-inch holes were then drilled through both ends of the rear housing. This will facilitate rosette welds to secure the new spindles.

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08 With the new spindle slid in place and centered, a small tack weld was added to keep it in place prior to final welding. Currie also made sure the spindles were clocked properly for the Wilwood disc brake backing plates.

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09 It’s obvious by these beautiful welds that Currie does this all the time. The axle tube was fully welded to the spindle around the entire circumference and the four holes were filled with welding rosettes.

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10 With the spindle in place, we could then install the brake backing plates, which also house the parking brake parts. Before screwing in the fasteners, we hit them all with some red Loctite.

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11 To carry the weight of the car, Strange went with some stout Timken bearings. These were the biggest ones they could use that would still fit inside the drive hub. In the back you can see the red seal, then two bearings with a bearing preload spacer between them. We mocked this up so you could see how the arrangement works. They are actually installed inside the drive hub after being packed in grease. The preload tapered bearing setup eliminates any play in the bearings, which further reduces any chance of piston knockback.

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12 Entering the home stretch, we then secured the drive hubs to the specialized Wilwood rotor hats. The Strange kit will ship with standard 11-inch rotors, but buyers can also upgrade to the 14-inch GT slotted Wilwood rotors we’re running.

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13 We then packed the bearings in Swepco 101 moly grease and installed them into the drive hub, tapping in the Timken seal last.

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14 The rotor/drive-hub assembly was then slid on the spindle and secured using the lock collar and spindle nut. Make note that the spindle nut goes on with the chamfered side facing the wheel, as shown. The spindle nuts were torqued to 75-85 ft-lbs using the supplied tool.

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15 The steel drive plates are what actually transfer the power from the diff to the wheels. They’re held to the drive hub by two small Allen bolts, but the load is carried by the wheel studs. The drive plates had O-rings on the back to help seal in all the bearing grease.

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16 The last and arguably most critical piece of the floater puzzle are the Hy-Tuf axles. Before being inserted, we installed the supplied snap rings on the 24-spline outer ends. These rings keep the axles from sliding inward and beating the crud out of the centersection. The outside axle is a course 24-spline, common to NASCAR and other forms of oval track racing.

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17 Prior to installing the O-ringed cap, we coated the axle end with a nice layer of high-pressure lubricant. When ordering your floater system from Strange, make sure to tell them what the inner diameter is for your wheel centers.

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18 Since we were in the neighborhood, we took this opportunity to swap out Bad Penny’s 3.89 gears for a set of Motive 3.50s. We also had them fully polished before bolting them to our Detroit TruTrac posi and installing it all in our aluminum Strange case. When we were running the standing mile, our Camaro was running out of Fifth gear at 172 mph. That won’t be a problem now, and we should also see an mpg benefit on the highway.

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19 All done and ready to stuff back under our ’68. In the end, all of the math that Currie did paid off, and our flange-to-flange distance came in at 551⁄16 inches, which is pretty darn close to perfect.

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20 Back over at Don Lee Auto, we installed the new floater rearend and bolted on the killer W4A forged nickel-plated Wilwood calipers.